Is Coffee Healthy? We bust myths about coffee

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Probably all of us have heard this question at least once. Is Coffee Healthy? Coffee is a drink around which many myths have been created. You can even say that it is a product shrouded in understatements and contradictory theories. We have been told more than once that this popular, aromatic infusion has a negative impact on health. On the Internet and in the color press, you can read, among others, headlines such as “coffee flushes out magnesium”, “children should not drink coffee”, “coffee raises blood pressure” and “how can you drink so much coffee, it dehydrates the body” … Such statements only increase disinformation. As a result, there are still many opponents of coffee, who maintain the position that coffee is “evil”. Despite this, in recent years interest in coffee, its consumption and effects on the body has increased among experts in human nutrition. Thanks to this, many analyzes have been conducted to refute these myths. So let’s see what’s in the coffee.

Coffee is a source of polyphenols and caffeine

Coffee is rich in antioxidants. The purpose of these substances is to capture free radicals that negatively affect the human system. Free radicals are the cause of oxidative stress, which manifests itself in the form of inflammation, general weakness, drowsiness, muscle and joint pain, and digestive problems. [3] Studies show that drinking coffee is associated with a reduced risk of coronary heart disease, type II diabetes, Alzheimer’s disease and may support the treatment of colorectal cancer [4], [5].

Antioxidants include polyphenols, organic chemical compounds with strong antioxidant properties. Studies indicate that coffee is the richest source of polyphenols in the Western diet. [27] Among the main polyphenols of this infusion is chlorogenic acid. Studies have strongly suggested that it can have anti-inflammatory and antibacterial properties. [6] Coffee also contains high concentrations of melanoidins, which are produced when the beans are roasted and give them a brown color.

In addition, coffee also contains trigonelline, from which vitamin B3 is formed when the beans are roasted, which is associated with supporting memory functions. [7] [8]

Which coffee has the most polyphenols?

A study conducted on different varieties of coffee proved that instant coffee is characterized by the highest antioxidant activity and total polyphenol content. In addition, the extension of the infusion time did not significantly affect the antioxidant activity of the tested infusions, and those obtained by pouring coffee grounds with water were characterized by significantly lower antioxidant activity and polyphenol content compared to other infusions. [9]

How much caffeine is too much?

An important addition to coffee is also the caffeine found in its seeds. [1] In 2015, the European Food Safety Authority (EFSA) published a scientific opinion on the safety of caffeine consumption, according to which a daily intake of up to 400 mg of caffeine and a single dose of 200 mg does not pose a threat to the safety of the population. [2]. Drinking more than 5 cups a day is considered excessive consumption. This is related to taking too much caffeine. Side effects may include sleep disturbances or heart palpitations. [28] It should also be remembered that pregnant and lactating women should not exceed the recommended dose of 200 mg of caffeine per day. Consuming caffeine above a safe dose can cause a miscarriage. Moreover, excess caffeine in the diet during pregnancy can also lead to low birth weight in the baby [29]. In addition, the recommended safe level of caffeine for children and adolescents is 3 mg/kg of body weight. [2]

It is worth mentioning that the caffeine content in coffee depends on factors such as the origin of the seeds or the method of preparation of the drink. For example, 60 ml of espresso contains 80 mg of caffeine, while 200 ml of filtered coffee contains 90 ml of the substance. So, coffee, coffee is not equal. [2]

Effects of coffee on health

Reducing the risk of type II diabetes

Studies so far clearly show that there is a lower risk of developing diabetes in people who regularly drink coffee. [11] In addition, a different animal study showed that consuming the coffee ingredients chlorogenic acid, quinides, lignans, and trigonelline improved glucose metabolism. Moreover, 12 cohort analyzes conducted in Europe, the United States and Japan examined habitual coffee consumption in relation to the risk of type 2 diabetes. The results showed that high coffee consumption was associated with a significantly lower risk of developing type 2 diabetes. Decaffeinated coffee provided similar The results suggest that the components of decaffeinated coffee may also have a positive effect on reducing the risk of the disease. [10]

The therapeutic benefits of coffee in Alzheimer’s disease

Epidemiological analyzes increasingly indicate that coffee may be an effective treatment for Alzheimer’s disease. A study of mice given caffeine in their drinking water from early adulthood to old age showed protection against memory loss and a reduction in an abnormal protein (amyloid-β) in the brain believed to be essential in the pathogenesis of Alzheimer’s disease. Moreover, memory and Aβ levels in the brain were restored in “old” cognitively impaired mice. The results show the surprising potential of moderate caffeine consumption (400 mg per day in humans) as an option for treating Alzheimer’s disease. [12] [13]

Coffee and liver disease

A study conducted by the medical department of the University of Southampton in the UK, led by Dr. Olivier Kennedy found that drinking three to four cups of caffeinated or decaffeinated coffee a day reduces the risk of developing chronic liver disease. According to the analysis, coffee drinkers are 21% less likely to develop liver disease. [21]

Coffee and the cardiovascular system

Cardiovascular diseases are one of the most common causes of death. [15] Modifiable factors include: lack of physical activity, smoking, excessive alcohol consumption or improper diet. Coffee is also often included in this group. However, an analysis of 250,000 respondents from 2017 confirms that drinking coffee is associated with lowering blood pressure. [16] This is due to the presence of polyphenols, vitamin E and niacin in coffee, which work against caffeine, which raises blood pressure. What’s more, it was recorded that after drinking coffee once, the blood pressure increased, but people who regularly consumed black infusion did not show this effect. [17] On the other hand, patients suffering from hyperlipidemia are recommended to limit or eliminate coffee consumption, due to kahweol and cafestol, which increase the level of cholesterol and triglycerides in plasma, which may cause abnormal metabolism. [18]

Coffee and supporting the treatment of colorectal cancer

A study conducted on a group of 1,599 patients in Boston showed that the consumption of at least four cups of both decaffeinated and traditional coffee reduced the number of deaths from colorectal cancer. [19] In addition, coffee has a beneficial effect on the state of the intestinal microbiota. This is because after drinking coffee, the population of beneficial intestinal bacteria Bifidobacterium spp increases. The previously mentioned polyphenols and, above all, the mentioned chlorogenic acid, may also be valuable for the microflora. [21]


So, is it worth believing in the myths about the aromatic infusion that we so eagerly reach for every morning? Definitely not. Coffee is characterized by a wide range of substances that have a positive effect on health or the fight against diseases. Thanks to the constantly conducted research, the knowledge about coffee and its substances is constantly being deepened. However, it should be remembered that, like everything else, coffee can also be overdosed. Long-term caffeine abuse can cause addiction, otherwise known as caffeineism, and this is associated with insomnia, muscle pain, anxiety, or heart disease. [22] [23]

Frequently Asked Questions

Is coffee healthy for the heart?

Studies indicate that regular coffee consumption is associated with lowering blood pressure. However, it should be remembered that people suffering from cardiovascular diseases should agree on the consumption of coffee with a specialist. In the case of people suffering from hyperlipidemia, it is recommended to limit or completely stop drinking coffee.

Is coffee healthy for the liver?

Studies conducted in the UK have proven that consuming three to four cups of coffee, with or without caffeine, has a positive effect on the prevention of chronic liver disease. According to the analysis, coffee drinkers are 21% less likely to develop liver disease.

Is coffee healthy for teenagers?

According to the European Food Safety Authority (EFSA), children and adolescents can also consume caffeine at the recommended daily dose of 3 mg/kg of body weight (other sources should also be considered).

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Is coffee healthy for the intestines?

Definitely yes. Studies have proved that it has a positive effect on the proper functioning of the intestinal microbiota, what is more, regular coffee drinking can significantly contribute to the prevention of colorectal cancer.

Why is coffee unhealthy?

Coffee is not unhealthy. Thanks to current research, there is more and more evidence that coffee can have a positive effect on the work of the human body and is willingly consumed in the prevention of many diseases. However, always remember not to exceed the daily recommended amount of caffeine during the day (400 mg). Overdose can be associated with insomnia, muscle pain, anxiety, and heart disease.

Is coffee with milk healthy?

Many people claim that adding coffee to milk, for example, can slow down or reduce the effect of caffeine, but this is a misconception. In a psychopharmacological study using caffeinated drinks, it was proven that the addition of milk independently improved mood every 30 and 60 minutes after drinking, and had no effects other than organoleptic. Moreover, no significant change in blood caffeine levels was observed. [14]

Is Cereal Coffee Healthy?

Cereal coffee is primarily a good alternative for people who, for various reasons, cannot consume coffee containing caffeine. What’s more, thanks to the fiber content, it can positively affect the work of the intestines and the feeling of satiety. In addition, it is willingly given to children from 3 years of age.

Is instant coffee healthy?

It has been given a bad reputation by many, but not properly. Studies have indicated that it contains the largest number of polyphenols, thanks to which it has a high antioxidant effect. [24]

Does Coffee Deplete Magnesium?

The subject of magnesium leaching by coffee is already known to everyone. We can dispel the fears of coffee lovers because magnesium losses with urine are insignificant, and what’s more, coffee also provides magnesium to the body (12 mg / 100 g of drink). [25] [26]


  1. Babik, K. (2020, April 9). Kofeina – pomaga czy szkodzi? Journal of NutriLife.
  2. European Food Safety Authority. (2015, May 27). Caffeine
  3. F, A. (2022, January 14). Stres oksydacyjny – co to jest i jak się objawia? Apteka Cefarm24.
  4. Wierzejska R.: Can coffee consumption lower the risk of Alzheimer’s disease andParkinson’s disease? A literature review Arch Med Sci., 2017, 13(3), 507–514,
  5. Mirmiran P, Carlström M, Bahadoran Z, Azizi F. Long-term effects of coffee and caffeine intake on the risk of pre-diabetes and type 2 diabetes: Findings from a population with low coffee consumption. Nutr Metab Cardiovasc Dis. 2018 Dec;28(12):1261-1266.
  6. Markowska-Jędra, A. (2021, January 15). Kwas chlorogenowy | Zielona kawa. NeuroExpert.
  7. Satheeshkumar, N., Mukherjee, P. K., Bhadra, S., & Saha, B. P. (2010). Acetylcholinesterase enzyme inhibitory potential of standardized extract of Trigonella foenum graecum L and its constituents. Phytomedicine : international journal of phytotherapy and phytopharmacology17(3-4), 292–295.
  8. Stanek, N., Zarębska, M., Biłos, Ł. et al. Influence of coffee brewing methods on the chromatographic and spectroscopic profiles, antioxidant and sensory properties. Sci Rep 11, 21377 (2021).
  10. van Dam R. M. (2006). Koffieconsumptie en het risico van diabetes mellitus type 2 [Coffee consumption and the decreased risk of diabetes mellitus type 2]. Nederlands tijdschrift voor geneeskunde150(33), 1821–1825.
  11. Fausta Natella, Cristina Scaccini, Role of coffee in modulation of diabetes risk, Nutrition Reviews, Volume 70, Issue 4, 1 April 2012, Pages 207–217,
  12. Basurto-Islas, G., Blanchard, J., Tung, Y. C., Fernandez, J. R., Voronkov, M., Stock, M., Zhang, S., Stock, J. B., & Iqbal, K. (2014c). Therapeutic benefits of a component of coffee in a rat model of Alzheimer’s disease. Neurobiology of Aging35(12), 2701–2712.
  13. Arendash, G. W., & Cao, C. (2010). Caffeine and Coffee as Therapeutics Against Alzheimer’s Disease. Journal of Alzheimer’s Disease20(s1), S117–S126.
  14. Quinlan, P., Lane, J., & Aspinall, L. (1997). Effects of hot tea, coffee and water ingestion on physiological responses and mood: the role of caffeine, water and beverage type. Psychopharmacology134(2), 164–173.
  15. Xie C., Cui L., Zhu J., Wang K., Sun N., Sun C.: Coffee consumption and risk of
    hypertension: A systematic review and dose-response meta-analysis of cohort studies.
    Journal of Human Hypertension, 2018, 32(2), 83–93.
  16. Xie C., Cui L., Zhu J., Wang K., Sun N., Sun C.: Coffee consumption and risk of
    hypertension: A systematic review and dose-response meta-analysis of cohort studies.
    Journal of Human Hypertension, 2018, 32(2), 83–93. 
  17. Godos J., Pluchinotta F., Marventano S., Buscemi S., Volti G., Galvano F., et al.: Coffee components and cardiovascular risk: Beneficial and detrimental effects. International Journal of Food Sciences and Nutrition, 2014, 65(8), 925–936. 
  18. Rodríguez-Artalejo F., López-García E.: Coffee Consumption and Cardiovascular
    Disease: A Condensed Review of Epidemiological Evidence and Mechanisms. Journal
    of Agricultural and Food Chemistry, 2018, 66(21), 5257–5263.
  19. Hu Y. i wsp.: Association between coffee intake after diagnosis of colorectal cancer and reduced mortality. Gastroenterology 2017;
  20. Jaquet M. et al. (2009) Impact of coffee consumption on the gut microbiota: a human volunteer study. Int J Food Microbiol,
  21. Kennedy, O.J., Fallowfield, J.A., Poole, R. et al. All coffee types decrease the risk of adverse clinical outcomes in chronic liver disease: a UK Biobank study. BMC Public Health 21, 970 (2021).
  22. Nawrot P, Jordan S, Eastwood J, et al. Effects of caffeine on
    human health. Food Addit Contam 2003, 20 (1): 1-30.
  23. Duarte PM, Marques MR, Bezerra JP. The effects of caffeine
    administration on the early stage of bone healing and bone
    density. A histometric study in rats. Arch Oral Biol 2009, 54:
  24. Mojska H, Gielecińska I. Studies of acrylamide level in coffee and coffee substitutes: influence of raw material and manufacturing conditions. Rocz Panstw Zakl Hig. 2013;64(3):173-181.
  25. Kynast-Gales, S. A., Massey, L.K. (1994). Effect of caffeine on circadian excertion of urinary calcium and magnesium. Journal of the American College of Nutrition,13(5), 467-472  
  26. Beata Przygoda, Hanna Kuchanowicz, Irena Nadolna, Krystyna Iwanow, 2020. Wartość odżywcza wybranych produktów spożywczych i typowych potraw
  27. El-Messery, T. M., Mwafy, E. A., Mostafa, A. M., El-Din, H. M. G., Mwafy, A., Amarowicz, R., & Özçelik, B. (2020). Spectroscopic studies of the interaction between isolated polyphenols from coffee and the milk proteins. Surfaces and Interfaces20, 100558.
  28. Abalo, R. (2021). Coffee and Caffeine Consumption for Human Health. Nutrients, 13(9), 2918, doi: 10.3390/nu13092918.
  29.  Temple, J. L., Bernard, C., Lipshultz, S. E., Czachor, J. D., Westphal, J. A., & Mestre, M. A. (2017). The Safety of Ingested Caffeine: A Comprehensive Review. Frontiers in psychiatry, 8, 80.